Hydraulic transmission



oct. 3..,y 1944. F, o, JQHNSO 2,359,423

HYDRAULIC TRANSMISSION lime@ r gaie/'M Offb/2223022 Oct. 3, 1944. F. o. JoHNsoN HYDRAULIC TRANSMISSION 8 Sheets-Sheet 2 Filed March- 31, 1941 l RN .om

fzzverzfor' Frederick adb/212.3012

Oct. 3, F. Q JOHNSQN r 2,359,423

HYDRAULIC TRANSMISSION Filed March 51, 1941 8 sheets-sheet s Oct. 3, 1944. F. o. JOHNSON HYDRAULIC TRANSMISSION o' Sheets-Sheet 4 Filed March 31, 1941 Frede? F. o. JOHNSON HYDBAULIG TRANSMIS SIDN B Sheets-Sheet 5 NEUTRAL Lvv- REVERSE Oct. 3, 1944. y F. o. JOHNSON 1 2,359,423

HYDRAULIC TRANSMISSION Filed March s1, 1941 8 sheets-sheet vl Z55 *c /172/0/7296.

Oct. 3, 1944. F.- o. .JOHNSON 2,359,423l

I HYDRAULIC TRANSMISSION Filed March 51, 1941 8 Sheets-Sheet 8 4Z-19' f' 92a f' f' l lIl 5 l' 207'/ ll l fiez/afar /TgqyederM O. fo/222507Z Y other types of motor driven vehicles.

@ UNITED STATES EATENT OFFICE for transmitting power at variable speeds and y"torque amplication ratios from internalv combustion engines used in connection with automobilestractors, trucks, buses, tanks, and many In addition, the invention may be'A applied to stationary combustion engine units requiring variable speed transmission. Moreover, many aspects and features of the present invention may well be employed in connection with prime movers of any conceivable type, Other than internal combusti,on engines.

The invention has for one of its primary objects the provision of a novel and useful power vtransmissionpf lthe vhydraulic type capable of effecting automatic speed and torque amplification changes in accordance with the load demand vof 'the driven member, to the end that power may be efficiently transmitted at the highest possible rate commensurate with the power input.

Another object of the invention is to provide a transmission of the above mentioned general type embodying a novel hydraulic pump and motor unit which is simple and sturdy", which embodies a'novel and extremely simple adjustment to produce variations in the transmission ratio between the driving and drivenmembers, which is capable 'of effecting torque amplification variable in 'minute increments between an exceedingly large amplification, if desired, and a oneto-one ratio between driving. and driven members, and which, when the latter condition obtains, d isplaces no fluid between the pump and,l

the motor, the unit automatically changing from a hydraulic torque amplifying coupling to a substantially iixedvdirect drive coupling.

It is a furtherobject of the invention to arrange the hydraulic units of the transmission system in such a manner that'the operating pressure uid flows between the pump chamber and the motor chamber through a single unrestrictedorifice plate, thereby obviating circuitous fluidA passage resistance to ilow and minimizing frictional losse'sand emulsiflcation tendency of the pressure uid.

It'is. a further object of the invention to provide a novel automatic control .coupling between 4driving and driven members which correlates speed' of rotation andloadgdem'and to vary the HYDRAULIC TRANSMISSION Frederick 0. Johnson, Chicago, Application March 31, 1941, Serial No. 385,991 .sc olaims. (ciao-19) Thefin'vention relates to devices for transmity., tingjpower from a prime mover to a driven mem- 2 @ber and,more particularly, to suchdevices eml bodying-'hydraulic apparatus capable of effecting automatica changes in the power-speed transmis- ,i sion ratios between driving and driven members. The necessity 'for such transmission devicesvand their wide variety ofdilds of application are generally well known.` For' example, apparatus of the present invention may be employed transmission ratio in response to a balance position between reacting torque and -centrifugal `force at such coupling.

Itis another object of the' invention to provide a novel form of hydraulic transmission in-f herently and normally capable of leil'ecting so called .free wheeling of the vehicle with which it is associated.'

It is a still furtherv object to provide novel means for controlling the transmission to. eifect any desired degree of braking between direct motor dragand complete locking of the drive shaft.

It is another object of the invention to pro` vide a novel transmission mechanism of this type visory controll of a single operators control lever and a foot throttle or accelerator pedal.

In conjunction with the'foregoingr object it is a further object of the invention to initiate a controlled transmission operation by the initial depression of .the accelerator pedal prior to motor acceleration which operation, upon motor acceleration, is effective to establish a particular Itype of drive depending upon the setting of the operators control lever.

Further objects and advantages of the invention will become apparent as the following description proceeds, taken in connection with the accompanying-drawings, in which: e,

Figure 1 is a diagrammatic layout of a system embodying the features of my invention as applied'to an automotive vehicle ofthe internal combustion engine type.

Fig. 2 is an enlarged, fragmentary, detailed view of a device capable of compensating for fluid expansion.

Fig3 is a, sectional view taken on line .3-3 of Fig. 4 is a. longitudinal cross-sectional view Aof a transmission embodying features o f the invention. y

Figs. 5 and 6 are enlarged cross-sectional views taken on lines 5-' 5 and-*G-B, respectively, of Fig. 4.

Fig. '1 is an'enlarge'd cross-sectional view taken Figs, 8 and 9 are views similar to Fig. 7 on a reduced scale showing the centrifugal elements of the control couple in intermediate y'and innermostV positions, respectively.

Fig. 10 is 'an enlarged sectional'view taken on line III-,III of-Flg.-4.

Fig. 11 is an enlarged fragmentary end face view of the mechanism shown in Fig. 4 and looking inthe direction of the arrows of line II-II.

Fig. 12 is a fragmentary plan view of' the mechanism shown in Fig. 11.

Fig. 13 shows a selector mechanism in its various control positions.

Fig. 14 is a vector diagram explanatory of the mechanism shown in Figs. '7, 8 and 9.

Fig. 15 is an exploded perspective view on an enlarged scale, showing in detail certain elements of the automatic control mechanism.

Fig. 16 is an end view, partially in section, illustrating a control valve and vacuum motor used in connection with the automatic control.-

` spectively, of Fig. 17.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do notthereby intend to limit the invention to the specific form disclosed, but yintend to cover all modifications and alternative constructions falling within thev spirit and scope of the invention as expressed in the appended claims.

Referringmore particularly to Fig. 1 of the drawings, I have shown therein, diagrammatiwith the drive shaft, andthe latterfor motor unit, has a rotor rigid with a transmission shaft.`

Adjustable means for vchanging the relative ec ltion ratio .between the shafts to a one-to-one ratio; When the latter condition obtains, fluid pumping action ceases and the entire pumpmotor unit,. together with its housing, rotates with the shafts as a xed direct driving coupling.

As seen at the left end of Fig. 4 (the forward end of the transmission) a flywheel is suitably secured, as by bolts 26, to a flange 21 of a crank shaft (not shown) A drive shaft 29 is secured centrally of the flywheel for rotation therewith by a multiple spline connection 28. drive shaft extends rearwardly into the pumpmotor housing 30, 3I preferably through an oil seal or packing gland 32 of any suitable type to seal the housing against fluid leakage along all the shaft. 'Ihe housing proper for this unit comprises two parts, a pump housing and a motor housing 3| drawn together in fluid sealing relation at their meeting edges 33 by a suitable bolt and tapped-hole arrangement 34, as shown.

While the unit II, I2 is acting as a torlque amplifying coupling, provision must be-madffor relative rotational movement between the housing and the shaft 29. While'the unit serves as a cally, an exemplary form of hydraulic transmission in connection with an internal combustion automobile engine I0, and embodying apparatus in accordance with my invention. In

brief, this engine drives a hydraulic pump II (Fig. 4), which Idelivers pressure fluid to a hydraulic motor I2 connected, through an automatic torque-speed control couple I3, to some driven member, illustrated herein simply as a shaft I4, but which might well be, of course, any

one of a. number of driven devices. The transmission system is controlled automatically by a pressure piston-mechanism I5, a selector mechanism I6, and a fluid valve :mechanism I1, all

under the supervisory control,of manual devices, herein illustrated in connection with a foot throttleor accelerator I8 and a hand lever AI9 mounted, for convenience, on a conventional automobile steering column 20.

Since the pump II and the motor I2 constitute the basis of the speed-change torque amplification coupling between driving and driven members, an intimate understanding of their functionand operation is desirable preliminary to a description of the devices employed for their control. Accordingly., the unit comprising the pump and motor elements will be described in detail first.

Generally, the objects of this unit (illustrated in Figs. 4, 5 and 6) are attained, in the present e embodiment, by employing. as part of the driving- `connection between two shafts, a pair of rotary hydraulic units of the radially slidable vane type, coaxially mounted in a housing and adapted to deliver and receive, respectively, pressure fluid through av ported division plate, constituting a valve, mounted between them. The former,

direct drive coupling, there is no relative rotational movement between the flywheel 25, 'the shaft 29 and the housing 30. Accordingly, to provide a simple and sturdy assembly for these parts, the housing is journaled directly in the flywheel and the shaft 29 is journaled within the housing. Thus, the housing is provided with a pilot head or bearing sleeve 35 in which the drive shaft 29 is suitably journaled for rotation, asby a ball bearing 36. An annular groove 31 adapted to receive the outer race 38 of a ball bearing 39 is formed concentrically on the flywheel, while a complementary 4inner race 40, adapted for cooperation therewith, is mounted on the exterior surface of the pilot head 35. Similarly, a transmission shaft 4I is-journaled for rotation in the opposite end of the housing by means of a. suitable bearing 42 and the housing is sealed against leakage along the shaft by a. suitable oil seal 43. The drive and transmission shafts are coaxially alinedwith the end of the latter suitably journaled in the adjacent end of the former, as indicated at 41. The shafts I2li and 4I carry rotors 48 and 49, respectively, situated withinthe pump housing 30 and the motor housing 3|, respectively, and each is adapted to carry a plurality of radially slidable pumping, vanes 50. The inner bores 58 andf59 of the pump and motor housings,'respectively, are eccentric to the axis of the pump and motor rotors and are of equal diameter. Withy bores 58 and 59 of the housings 30 and 3|, the

. or pump unit. has a vane carrying rotor rigid 75 interiors of said rings being indicated at 62 and 83. The relationship is such that the centers of the eccentric sleeves 60 and 6I can be made to coincide with the axes of the rotors, or, upon selective rotation of the sleeves within the bores The.'

tures 48 and 49. Each vanehas an outer bearing head formed with a curved surface having the same radius as that of the inner surface of the eccentric sleeves and adapted for close running engagement therewith. The bearing heads 5I are mounted upon the `vanes for rocking movement,

each being formed with a curved surface in con-v tact with the outer curved edge of the vane.

` Thus, the outer bearing surface will register uniformly on the inner' surface of the eccentric sleeve regardless of the angular disposition of the vane within the housing. Each rotor is provided with a pair of floating rings 54 carried within recessed lateral grooves 55 of the rotors for supporting the inner ends of the vanes to maintain their conmetry of the pump and motor-'rotate only one half the angle of rotation of the eccentric sleeves centric spaced relationship with respect to the sleeves. Formed on the inner lateral edges of each vane are shoes 51 adapted to bear on the rings 54. The inner edge of each shoe is rounded to provide an arcuate cani surface which com- 4 pensates for changes in the angular' disposition of the'vanes with respect to the sleeves and rings as the hydraulic units are adjusted between zero upon adjustment. Accordingly, provision is made for rotating the valve plate 64 concurrently with, but only'one half the angle of rotation of thev sleeves. Thus, a cluster gear is mounted peripherally of the sleeves .and within the housing 30, 3| and comprises three gears, the two outer gears 61 and 68 of which rotate the sleeves 60 land 6I, respectively, while the inner gear 69 rotates the ported division plate. 'I'he vlatter gear 69 is of such a size as to rotate the plate oney fluid will be displaced from the pump to the and maximum eccentricities (see Figs. 5 and 6). f

The radial' distance between the oating rings 54 and the inner peripheries of the sleeves is always equal, butftheyanes are disposed at a slight angle to the radius when other than concentricv conditions obtain. The arcuate cam surfaces of the shoes are so formed as to compensate for this change' in effective length of the vanes.

Within the housing 30, 3l and between A the pump and motor rotors a division plate 64 is.

provided, Vwhich serves to port pressure iiuid from the pump to the motor and also exhaust fluid from the motor to the pump. To this end, arcuateinlet and outlet ports 65 and' 66 are formed in the division plate-64. The, eccentric sleeves 60 and 6| are mounted within the pump and motor housings so that the inner bore of the pump sleeve '60 is concentric with the axis of the pump rotor 48 when the motor sleeve 6I is in its position of maximum eccentricityrelative to the motor-rotor. This is the neutral setting, in which position rotation of the pump rotor will cause fluid to be carriedaround with the vanes but none will be displaced from the pump housing to the motor housing and nopower will be transmitted.

to the motor rotor. o i

Means are provided for rotating the -sleeves 60l motor, and power will be transmitted from the pump rotor to the motor rotor. Initially iiuid displacement will be in small quantities to effect a large torque amplification between the driving and transmission shafts, fluid displacement gradually increasing as the cluster gear is rotated until'thedegree of eccentricity of each ofthe chambers coincides. At this point power is transmitted between the shafts at a ratio of onel to one.

Upon operation of a closed hydraulic system of this type for any appreciable length of time, a certain amount of heat develops causing the fluid medium tol expand. Expansion in the working chambers of the pump motor might result in a building up vof pressure in the interiorlof the rotors 55 and around the bearings 36 and 42 beyond the capacity of the oil seals. To accommodate expansion and prevent fluid loss a pair and `6l simultaneously to increase the pump rosimultaneously and' in the same direction, but

i the recess in the motor rotor.

-of automatic by-pass valves (Figs. 2, 3 and 4) leading to expansion bellows `13'o n' the motor chamber are incorporated. A bore 14 is formed in the motor housing having a. port opening to the interior of the motor chamber in the area of throughA a check valve'16 with the expansion bellows 13. The bores 14 and 15 may be suitably the effect is to vary the eccentricities of the pump f an motor chambers in opposite senses. In operation, one-half of the pump chamber receives erhaust fluid from the motor Awhile the other tor chambers as to position their centers 90' apart andthe valve plate 64 is positioned so as to dispose'its arcuate ports 65 and 66, respectively, on each side of the axes of symmetry. Due to the eccentric mounting of the sleeves within .the -housing 50, 3l, the coincident axes of symclosed by a pair of plugs 11 and 18, respectively,

the latter having an extended inner end portion- 19, whichcarries the check valve 16. Fluid leak-- age dueto expansion or otherwise from the pressure fluid chambers to the interior of therotors is brought-back to the working chambers through the bore 14 to the expansion bellows 13,v and thence through the check valve 16 to the exhaust or low pressure side of the -motor chambers. The check valve 16 prevents the fluid in the pressure chambersV of the motor from short circuiting and also prevents fluid under'pressure from passing into the bellows. Conveniently, the bores 14 and 15 may be employed for filling thesystem with hydraulic fluid. v

Since the housing 30, 3| is, under certainconanions, a freeY body, freely rotatable relativo to' its associated mechanisms, pumping action will tend to 'cause it to rotatein one direction or another, depending upon the conditions of eccentricity of the pump and motor chambers. Upon initiation of pumping action,. that is, when the This bore comestacas c e inside ci; the motor chauber acts through ger moment arm than does that in the ber, thereby tend". .he the opposite i Jc on from the rcoi the rotors. n the sleeves have rotated approrimate;4 90 from tita neuu i itiou, the chan-fiber4 of the pump a L nio have the same e entricity and the rowill rotate at the same speed. The resultant e on the circurnierences oi the pump and chambers will be equal and opposite, ugly, there will no tendency for the to rotate except from frictional drag. rotation of the sleeves only very slight- Ey more than 90 will cause a resultant pressure on the circumference of the pump chamber to act on a. longer moment arm than that the motor chamber and wili thereby cause the housf to rotate in the same direction as that of rotors and also at the same speed.' when .his condition obtains, pumping action ceases, no iiuid is displaced from the pump to the motor the entire unit rotates as a fixed direct drive coupling.

Selectively adjustable means are provided for controlling the rotation of the housing 3o, .tl un der various driving conditions, as, for example, when the transmission is used in connection with an automotive vehicle. During normal forward speed operation, the housing must be locked against reverse rotation during the initial stages of acceleration, when the transmission is operating as a torque amplifying coupling and until a one-to-one ratio is reached. At the latter stage rotation of the housing must be permitted in the direction of rotation of the rotors to effect direct drive coupling. Similarly, during braking and during reversing, in which latter condition direct drive coupling is not used, the housing must be locked against rotation in either direction. As will be seen in Figs. 1, 4, l1, 12 and l5, the means for controlling the rotation of the housing comprises an overriding clutch mechanism, generally indicated at 89. An extended bell housing 8| is bolted, as indicated at 82, to the rear side of the housing 30, 3| and is journaled for rotation with the housing 39, 3| by means of a suitable bearing 83 in a stationary frame member 84 of the automobile. An annular ring 85 is splined, as at 86, to a. hub portion 81 of the bell housing 8| and has an outer ring gear 88 having teeth adapted for engagement with internal teeth 89 in a lock ring 90. The outer ring gear 88 is, an overriding clutch and is carried by the ring 8'5 for free rotation inthe forward-speed direction and is lockedagainst rotation in the reverse direction. In this instance, it comprises a roller type frictional ratchet gearing mechanism 9| (see Fig. 11), having a conventional roller and ratchet wheel arrangement. Upon rotation in one direction, the rollers 92 between the ratchet Wheel formed on the ring 85 and the outer ring 88 are wedgedbetween the wheel and the ring as they move up the inclined edges of the teeth. The lock ring 90 is longitudinally slidable on studs 93 along the axis ofthe driving and. driven shafts and is constrained against rotation by means of the studs 93 which are screw-threaded in the frame 84. ',Ihe annular ring 85 is provided with an annular clearance space 94 with which the lock ring is adapted to register longitudinally in the position shown in Fig. 4 for free rotation of i an ring ci the hoi associated w lever S postion the loci-Z i with the teeth oi ring gea speed, free wheeling and. l. g c., l2) io cgistration with the clearance space tlf; when tl transmission is .eutrai (poEl sition 'ol and f r registration with ring ge .s it? during reversing and braking (positions c and d), for purposes which Wili hereinafter become apparent. it will be seen that during normal forward-speed operation the loci: ring' of overriding clutch overcomes the tendency ci" housing Si to rotate in the opposite direction to the rotation of the pump and motor rotors, but permits rotation in the direction of the rotors when they have reached a one-to-one ratio.

To provide for automatic variations in the torque amplification so that the most emcient regis power transfer may be attained commensurate with the output of the prime mover and the load demand ai; various speeds, means responsive jointly to tie torque resistance (load) of the driven shaft and to the speed of rotation lare connected to automatically vary the eccentricities of the pump and motor chambers. rFhe torque resistance of the driven shaft, in general eect, varies substantially inversely with the speed of rotation of the shaft. Theoretically, therefore, in order to obtain the most eicient transmission ratio, or the optimum balance between torque resistance and power input, at various speeds, i have provided an automatic control mechanism which operates on the principle of balancing the reacting torque exerted by the driven shaft against centrifugal force which is a function of the speed of rotation of the driven shaft. The mechanism consists of a exible, or loose coupling, generally indicated at I3, made up of two parts; a hollow ring-shaped housing element 95 splined, as at 96, to the transmission shaft and a ring-shaped disk element 91 rotatable within the housing element 95 and vrigid with the driven shaft l@ (see Fig. 4). 'I'he transmission shaft is coaxially alined with and suitably journaled within the driven shaft, as indicated at 98. The linkage between the two elements 95 and 91 is effected by means of centrifugal elements 99 having-pinsv or studs |00 extending through contour slots |0| and |02 in the faces of the elements 95 and 91, respectively, (see Figs. 7, 8 and 9). Power is transmitted directly through the pins from one element to the other.

conguration but arereversely formed in the elements 95 and 91 so that the reacting torque .be-l tween the transmission shaft and the driven shaft tends to hold the centrifugal elements inwardly against the centrifugal force exerted thereon by rotation of the shafts. .Thus the centrifuga] elements seek automatically a position in which the tangential force exerted by the slots on the pins as aresult of the torque produced by the motor rotor is balanced by the centrifugal force produced by the centrifugal elements on the pins in all positions. When the load 'is increased the centriugal elements tend to move inwardly and as `the load is decreasedr the elements move outwardthe housing in either direction. The annular 75 ly. Such motion causes relative rotational movement between the coupling elements 95 and 91 in nut are internal helical splines or threads ||4 which motion may be transmitted'to the eccentric. sleeves 60 and 6I`to eiTect variations in the torque amplification ratio commensurate with the I load demand at all speeds.

'rnc-curve of the contour 5101s ml fand lo: 1s generated from a for'mula in which the component F1 of the centrifugal force (Fc) exerted by the centrifugal elements on the slots is equated with the component Fi of the torque moment (F) exerted on the centrifugal elements as a result of the torque at the couple. Thus-referring to Fig.14, f

' FFW; F,='F sin a where a is the angle between the radius (r)v and the normal tothe' tangent to the curve. at the point of contact of r with the curve. Then Ft tan a "The centrifugal force (Fc) may be computed from the weight of the centrifugal elements, the acceleration due to gravity, the linear velocity of the elements at a particular speed and 4the vmomentarm (r) or distance' o f the element from its center of rotation. The torque at the control couple and, hencethe torque moment'at distance 1', may be computed from the maximum engine' torque (Ts) and the transmission ratio R (deter.- mined by the setting of the eccentric sleeves 60 and 6|) from the following formula F *IZ Accordingly, the formula,

pling I3 in accordance with the load speed requirementa The mechanism for .transmitting this relative control movement tothe eccentric sleeves 60 and `6I of the transmission unit to ef-Q fect automatic variations in the. torque ampliflcation ratio commensurate with the load demand, is illustrated in Figs.A 4, 10 andvl. It will be seen that'the ring housing v95 carries at one end a series of `fingers, I| for engagement -with internal slots |.II in the internal portion I2 of a compound nut which surrounds Vthe driven' shaft I4. Also cut in the internal portion of the which engage a helical spline sleeve II5, keyedA housings, 30, 3|and 6I, as will become apparent'. hereinafter. Yet, the longitudinal movement of the nut4 is unaffected by such relative rotationzV For transferring this longitudinal movement to the sleeves'60 and 6|, a disk |I9, rotatable on a hub of the ring housing 95, is provided with a hub |2| extending in concentric spaced relation 4to -the path of longitudinal travel of the nut II3. splines threads |23 formed on the external portion III of the --nut II3. Longitudinal movement ofthe nut"rotates disk II 9. The disk I|9 is formed with a, gear sector |24' over a portion of its peripheryiadapted for engagement with a gear |25. The gear |25 is rigid with a shaft |26 journaled 'for rotation in axially alined bores |21 and |28 in the peripheral walls of the housings 3| and. 8|. The forward end of.the shaft |26 carries the cluster gear' 61, 68, 69. Hencerotation of the hub |2| adjusts the eccentricity of sleeves 60 and 6|. Fingers |30, operatively associated' The sleeve has internal helical with manually supervised control means (hereinafter to 'be described) for the sleeves 60 and 6| are adapted for engagement with slots I3| formed in the external portion |I1 of nut II3.

vTheir function is to prevent the external portionfrom merely rotating on the internal portion during longitudinal movement of` the nut, thereby failing. to transmit rotary motion to the disk II9. The fingers |30 are operative, however, to rotate the external portion' of the nut in response to the manually supervised control means, to rotate the disk vI I9 and thereby adjust the eccentricity of sleeves 60 andGI to initiate power transmission.

. Relative rotational movement betweenthetwo parts 95 and 91 of the flexible couplingsIS is thus transferred to the eccentric sleeves 60and 6| to effect speed changes-in accordance with 'loadspeed requirements.

turn transfers it to the rin'g housing 95 and hence through the centrifugal elements 99 to the' disk 9`Iq'and driven shaft I4. As the speed of rotation of the driven shaft increases and the torque at the couple decreases, the centrifugal elements will tend to move outwardly in the contour slots as at IIS, to the driven shaft I4. Thus relative movement between the. elements 95 and 91 causes longitudinal movement of the nut I I3 along the shaft' I4 by screw action. The nut I I3 hasan external portion I I'I freely rotatable with respect to the inner portion I2 andmaintained in alinev ment' therewith by .a suitable thrust bearing,

to a position at which the component of lcentrifugal force, acting in the contour slots, balances `the torque demand component, also actingin these,V slots. As the centrifugal elements move outwardly, the transmission ratio decreases and the speed increases. When the driving and driven shafts are rotating at the' same speed, the condition of fixed direct'drive couplingwill prevail.' If' the load is increased beyond the point where the torque developed (at the speed at which the prime in over @is operating) -will balance the reacting torque, the centrifugal elements will move .-inwardly, causing. relative movement between ring housing and disk 91. This, in turn,`will cause the nut II3 vto move along the sleeve |I5 and, by screw action, cause thel disk I I9 to rotate with respect to the housings 30, 3| and 6|,which movement is transferred( to the eccentric sleevesl 60 land 6I through gear |25, shaft J 26 and cluster gear 61, 68 and 69. This movement will con-l tinue untilithe sleeves have been rotated suii- Lgiently to cause the transmission to .produce sufficient power torque amplification to compensateI for the increase in load, the whole unitag'ain functioning as a transmission rather than a direct drive coupling. As the load torque dimin- I22, which` 'engage external helical As the sleeves` 60 and 6I are moved from their neutral position, a driving torque is transferred to the motor rotorwhich in rfrom the pump to the motor through the influence of manually supervised control means, the fingers |30 which engage the external portion of the compound nut II3, are rotated. 'I'his movement obviously causes rotation of the sleeves nism I1. The piston |66 is suitably mounted in the cylinder for reciprocation and has a piston rod |61, connected by means of a slotted linkage |68 ywith the end of the control lever |53. The control lever is pivoted, as at |68, to a rigid bracket |10, so that motion of thpiston to the right (as seen in Fig. 4) will cause longitudinal movement of the nut |40 to the left.

A selector mechanism, generally indicated at I6, under the control of the hand lever I8, is

provided for limiting the movement of the con- 60 and 6| from their neutral setting to initiate movement and thereafter the transmission is controlled automatically by the couple. 'To this end a control element |32, freely rotatable on the driven shaft |4, carries the nngers |30. An internal gear |33 is formed on the flanged end of the element 32 for engagement with pinions |34 of gear elements |35 journaled in the hub portion 81 of the bell housing 8|. The gear elements |35 carry on their opposite ends pinions |36, which engage a'. peripheral gear |31 on a helically splined sleeve |38, which is also freely rotatable, on a bearing sleeve |39, on the shaft I4. The splined sleeve |38 is engaged by a nut |40 having complementary internal helical threads I4| which, when the nut is moved longitudinally along the sleeve |38, rotatesthe latter through the agency of its spiral-threaded engagement therewith. The nut |40 is internally slotted, as at |42, to receive fingers |43 of a iiangeddisk element |44, which is bolted, as at` |45, to the hub 81 of the housing 8|. The function of the fingered element |44 is to prevent rotation of the nut |40 relative to the housings 30, 3| and 8|.

Means are provided for imparting longitudinal movement to the nut`|40 to the end that rotational movement be imparted to the sleeve |38, hence to the pinion elements |35 and to the ngers |30. Referring to Figs. 4, 11 and 15, the nut |40 has an external portion |50, freely rotatable thereon, through the agency of a roller bearing |5|. 'I'he external portion |50 is connected, herein by a trunnion engagement |52,

. associated.

It will be understood that rotation of the sleeves 60 and`6| and the ported division plate 64 in one direction (counterclockwise, as seen in e Figs. 5 and 6) causes the transmission of power in a forward speed direction, that is, in the same direction as the prime mover. Rotation in the oppositedirection (clockwise, as seen in Figs. 5

and 6) lcauses reverse power transmission. Ac-

cordingly, provision is made for longitudinal movement of the. nut |40 under the inuence of the control lever |53 in one direction (to the left, as seen in Fig. 4) for` forward speed operation, and to the right for reverse.

Since it is desirable to operate the control lever 53 by vacuum power, which is ordinarily readily Yavailable in motor vehicles, a vacuum motor I5 (see Figs. 1, 4, 11 and 16) is suitably secured to the automobile'frame' adjacent the remote end of the control lever |53. The motor-comprises a cylinder I6| having suitable intake and exhaust ports |82 and |63 connected through trol lever |53 for forward, neutral, braking and reverse operation of the transmission. Referring to Figs. A4, 11, 12 and 13, the selector mechanism comprises a bracket |1| rigid with the bracket |10 and having grooves |12 and |13 for the reception of a slotted plate |14 slidable therein.

limit its movement by the vacuum motor |5 to a i The slotted plate is connected fory concurrent actuation, by the control lever I9, with the slidable locklring 90. 'Ihe linkage connection com- 'v prises a lever |15 rigid with the plate |14, having a slotted lost motion connection |16 with one arm |11 of a bell crank pivoted as at |18, to a bracket |83. The other arm |19 of the bell crank has a'sliding connection |80 with a trunnion |8| formed rigidly on the periphery of the lock ring 90. A rod |82, rigid with the bell crank at its pivot. point, extending at right angles thereto and journaled in brackets |83 (Fig. 11), carries a lever |84 having a sliding connection |85 with a trunnion |86, diametrically opposite the trunnion |8| on the lock ring 90. Linkage |81 and |88 (Fig. l) of any suitable type connect the bell crank with the hand lever `I9 for simultaneous actuation of the lock ring 30 of the overriding clutch mechanism 80 andthe plate |14 of selector mechanism I6.

The slidable plate |14 of' the'selector is slotted to Yreceive, the control lever |53 therethrough and central position (as seen in Fig. 13), when the hand lever I9 is in neutral position, to the left for forward" to the left for braking, and to the right for reverse Accordingly, the plate has a central longitudinal slot 200 and three lating in either direction when the plate is in forward position, the lock ring is registered with the ring 88 of the overriding clutch (position a) permitting` rotationV of the housing in a forward speed direction only; when the plate is in reverse -or braking positions, the ring is regisi vtered with the teeth 46 (position c or d) to preto hold the control lever centered when the 'mechanism is in neutral and idling" position;

to connect such, source of supply for actuation of the control lever for forward speed operation conduits |84 and |65 to the control valve mecha- 75 as an incident to initial accelerator^ depression;

'af shaft 233.

buretor 23 1 through linkage 238 (Fig. 1)".

to similarly control the vacuum motor for re- -versing and braking positions oi' the control lever; and to effect limit or incremental control Aof the vacuum motor during the braking operation. The valve in the presentv instance consists ofa valve body'204 (Figs. 16 to u23, inclusive) hav-v ing a central bore 205 and provided with six lonm it connected with conduit its, through. the

control lever in neutral position (Fig. 1 3). `A s the accelerator is depressed, this motion ds trans- 2 30-221, toerotate thev valve plug.. This causes the'vacuum line`2|6 to be connected with conduit |55, through the circuit` 2|62|1224 229-223-2 |4-201-244- 203-2I3-2I I -'22 |66. Similarly,` the atmosphere line 2|0 lecon-'- nected with conduit |64. through circuit 2| 3-226-228-225-2I5-2I0-245-299-22l- |64'. VThis setting causes the piston of the vacunected through a conduit 2| 3 which-communi;-

cates through a radial duct 2|'| with the central bore 205, and a radial conduit2l8 similarly communicates with the central bore and is vented to the atmosphere through a screen'2l9. The conduits |34 andl 65 which lead to the vacuum motor are connected through ducts 220 and 22| respecltively with the longitudinal ducts 209 and 2 I I respectively. A longitudinal slidable sleeve 222 is tted within the central bore and provided with 4parallelogram-slraped ports 223, 224, 225 -and 226 equally spaced peripheraltly of the sleeve and adapted to open to the radial ducts 2|4, 2|1, 2|5 and 218, respectively, in all longitudinal positions of the sleeve.

-Fitted within the sleever and-rotdtabie with respect to it is a valve plug 221- having ports-223 and 229 adapted to interconnect adjacent sleeve ports selectively upon rotation. The valve plug um motor to move the control lever into.'starting or engaging position, assuming th. selector to have been shifted to forward" or braking position. Further depression of the accelerator will not rotate the valve plug because of the contour .of the cam 23|.

As long as'the accelerator is suillciently depressed tomaintain the valve plug in this position, control lever movementsae unaffected and the transmission remains engaged in automatic control.' If the accelerator is brought back to its idling position, the valve plug rotates to reverse the connections and the transmission will be broughtlbackto neutral position. I A

In order` to cau'se the transmission to functionin reverse, the operators control lever I9l is shifted to "reverse causing rotation ofthe reversing plate 243, through` the connec- 221 (Figs. 16 and 17) projects outwardly from one end of the valve'body and carries eccentrically a pin 230 for engagement in a cam plate 23| which is oscillatable with a lever 232 about The lever 232 is connected with the accelerator I3 by a rod 234 and has a lost 'motion connection 235 with a lever 236 rigid with the shaft 233 which connects with the car- The cam curve is so formed that upon initial de-' pression of the accelerator, motion is transmitted through the rod 234 to the cam plate to effect a rotation of the valve plug.. Further depression of the accelerator affects theA carburetor, after the lost motion of connection'235 has beentaken up, but has no further effect on the valve vplug tions |9-25|-250- 249 .243 -243. Such movement causes the vacuum line 2| 6 to be connected with the conduit |65, throughthe circuit 2|6- |65, and the atmosphere line 2|8 .to be connected with the conduit |64, through the circuit A2|3- 220-I 64. Thus, when the accelerator is in idling i position and the selector plate|14 shifted to resion of the accelerator, the vacuum lin'e 2|5 is connected to the opposite end of the vacuum mo- Fitted in the right end ofthe vaive -body (Fig.

1"!) towhich the longitudinal ports open is a reversing plate 243 provided with ports 244 and 245 (Figs. 19-23) adapted upon rotational shift- 1 ingmovement to interconnect adjacent longi-l tudinal ports 201 with 208 and 2 09'With 2|0 or selectively 206 with 201 and 2|0 with 2||, l A rigid lever 243 on the reversing plate projects therefrom for actuation by a linkage 240 associated' Withta cam -250 (Fig. 16). The cani is operatively connected with the hand lever I9 on the steering column by a suitable linkage 25|.

position the valve plug connects the vacuum line l2||i with the conduit |64, through -the circuit 223 -2 |4--201-'244 2061-2 |2-203 22o-'- 64, and the atmosphere line 2|8 is connected to the conduit |65, through the circuit 2|8--226-220-7' 225-2|5-2|0'-245-2||-722|-|65. Thiscauses movement of the control lever 'into the reversing slot 20| 1 (Fig. ,13), thus actuating the compound s nut |40 td initiate reversing movement.

1 vehicle, as'fillustrated in Fig. .1, is as followsz' Assuming the operators control lever I9 to be in y neutral" posdt ion,-the look ring 30 of the 'over'- riding 4clutch mechanism will be in neutral position b, permitting free rotation of the pumpmotor housing, and the selector plate |14 will be in. nreutral position (Fig.v 13).

started, no fluid will be displaced tothe-motor chamber which is in position of maximum eccen tiiicity. With the accelerator, or foot throttle I3,

. in idling position, vacuum power is'connected through -the valve |1 to the vacuuin motor 'I5 tending to move the control lever 53 .to the right With the cen- .trifugal elements 99 in their outermost position,

(Fig. 13).

Depression of the accelerator with the parts in this position will have no effect on the control lever |53 since the selector plate holds it centered. To initiate forward movement of the vehicle, the operator simply moves the hand lever I9 to forward and depresses the accelerator. This movement of the hand lever positions the selector plate |14 for forward and engages the lock ring 90 in position a permitting forward rotation only of the pump-motor housing 30, 3|. Depression of the accelerator rotates the valve plug 221 to reverse the vacuum power connections and cause the piston of the vacuum motor to move the control lever |53 into the starting or engaging position (to the left). This movement is transmitted through the nut |40,l splined sleeve |38, pinion .elements |35, fingers |30 to rotatethe external portion II1 of the compound nut II3. This rotational movement is in turn transmitted to the eccentric sleeve 60, 6|, through elements |2I, IIS, |28,

which rotates the cluster gear to create eccentricity in the pump chamber, causing fluid displacement and power transmission to the transmission shaft 4I.

'In view of the large reactingtorque at the control couple I3 during starting, the centrifugal elements 99 will tend to move inwardly. Such movement tends to bring the eccentricity of the pump -chamber back to Zero, but as the nut |49 is moved to the left (Fig. 4) under the influence of the engaging control lever |53, this tendency is counteracted so that when the con` trol lever has reached the limit of its movement,

the degree of eccentricity of the pump and mo- CII tor chambers will be under the sole control of the centrifugal elements 99, which automatically seek a balance between the reacting torque and the centrifugal force. As long as the accelerator is depressed sufficiently to keep the valve plug 221 in this operating position, the transmission remains engaged in automatic control.

If the accelerator is brought back to its idling position the transmission will be brought back to neutral in which case the vehicle will be permitted to coast freely without motor drag, more the pump chamber so that free relative rotation may be had between thel pump lrotor which is rigid with the engine shaft and the housing 3U, 3|, 8| which is carried around by the motor rotor on the transmission shaft.

Similarly, in its normal setting for forward speed operation, the transmission functions as a so-called no back-up brake to facilitate control of the vehicle when starting and stopping on ascending grades. In this setting the housing 30, 3| 'is prevented from reverse rotation and, dueto the large eccentricity in the motor chamber and concentricity in the pump chamber, uid cannot be pumped in a reverse direction from the motor to the pump.

In order to cause the transmission to function in reverse, the operator's control lever I9 is moved to reverse position, causing the lock ring 90 to engage the annulus 45 of the overriding clutch mechanism ,to prevent rotation of the housing in either direction land causing the in Fig. 18h,

selector plate |14 to move to its reverse position. The reversing plate 221 is concurrently rotated to change the valve connections, to the end that the control lever |53 may be moved to its right handposition (Figs. 4 and 13) upon depression of the accelerator. Such movement causes the sleeve |38 to rotate in the opposite direction from that for forward speed operation and to transmit the control lever movement to rotate the sleeves 60 and 6| reversely from their neutral position. Thus, upon iiuid displacement, the motor rotor is rotated in the opposite direction from that of the pump rotor. While the transmission operates in reverse the automatic control couple mechanism I3 does not function.

It is frequently desirable and sometimes necessary that the transmission be used as an adjunct to the brakes in descending long steep hills. To this end the transmission of' the present invention is so arranged that 'it may be easily and simply controlled to effect any degree of braking between direct motor drag and complete locking of the driven shaft. This control is accomplished in the presen-t instance primarily by means of the sliding sleeve 222 of the valve mechanism I1. Braking is eiected by locking the pump-motor housing against rotation in either direction and limiting movements of the control levei` |53, under the influence of the valve controlled vacuum motor, to positively regulate the transmission ratio between the pump and the motor. Under these circumstances the load ytorque being reversed the degree of reverse lpumping action from the motor to the pump will determine the amount of braking. This incremental or limit control is determined by the degree of accelerator depression. In other words during the range of initial accelerator depression, prior to carburetor control, which causes rotation of the valve plug 2 21, the parallelogram-shaped ports 223 to 226 of the sleeve are so shifted as to permit only incremental or step-by-step movement of the control lever I 53 in response to step-by-step movements of the accelerator in its range of initial depression.

In the present instance these objectives are accomplished by mechanically connecting the sliding sleeve 222 with the piston of the vacuum motor, as by a nexibie shaft :so (Figs. 1 and 17).v

'to Figs. 16 to 19, inc., as the accelerator pedal is slightly depressed, the valve plug will be rotated to move its ports 228 and 229 from neu trai or idling" position as seen in Fig. 19 to the position shown in Fig. 18a, interconnecting parallelogram ports 223 and 224 on the one hand and ports.225 and 226 on the other. These valve connections` will cause the control lever |53 to start moving to engaging position as in normal operation when the accelerator is initially depressed; the limit of itspreliminary movement. Since, however, the sleeve-222 is connected to the piste/nio( `the vacuum motor, any movement of the contrl lever is transferred' to longitudinal movement of e sleeve. The ports of the sleeve being'prallelog -shaped or cut at an angle, longitudinam'ovement of the sleeve, as indicated will immediately close the openings between the .valve plug and the sleeve and contransmission will not be permittedA to go tol direct drive when the load torque is descending a grade but remains in anlinterm'ediatey ratio setting which depends on the 'ositionofg s ,ssams i 51 a variable .nism vempylising.,A in combination, 4coax'ii'slly anneadriving.'

' `ports of the sleeve. This results in further movo-v '15 capacity driving enectiom l close the communication between the 'sleeve ports 2o and valve plug ports (Fig. 18d). Movement ofl ports and-cause control lever movement. Ii the versely from the hydraulic motor chamber to the sion and driven shafts, a rotary pump unit on the accelerator pedal within its range-of depression. In the position be only a very slight eccent city in the chamber and since the housin'gfislo'cked l i rotation in either direction a of ma control couple means for H severe braking is eiiected. Furtherdepression control movement iresponsive:.1ointly; 'to t. of the accelerator pedal causes the valve plug to inthe speed of rotation and-the load torque rotate further, as seen in Flg. -18, again driven shaft,` means forv its ports within the range ofthe p suoli control movement to -adjust `sai .'l variable.A

capacity driving connectionbetwi'eenV saiddriving'and onsnsrtafa couple for transmittingl power between transmission shaft saidurivenssnait, said' ment of the control lever to produce a different transmission ratio 'settingin which the is less severe.- Such movement 'f-@the control lever, however, causes the sleeve 222 to move and 1.5.42"1'he-@mbinatien 01.- f 'ShaftLj-ianadilistable C `#011'. fordrivinggoneiiof iutidrshaitsfromtheg'othervr ativ variable torque ampliilcation ratios, 'oirunit including a pump housing"and 'a motorhousing together and mounted the accelerator pedal to the limit of its' initial Lfprf-rotetion-concentrically of the adjacent ends depression effects a condition of direct motor.' i foffsid^shafts. a}pair of eccentric sleeves ecdrag since the transmission then becomes fully mounted withinhousings to deengaged. If the accelerator pedal is raised,the fine-pump and motor chambers, said sleeves bevalve play will be rotated in the opposite direcrotatable to Verythe eccentricity between tion, to the position shown in Fig. 18. Upon said 'shafts andl the inner periplieriesl oit` said such -a reversal of connections the. piston of the iilievemY Uva-ne "een'yins rotors on said "shafts vacuum motor will commence to move in the oppump housing and said motor housposite direction causing the sleeve 222 to move to '3"0' \in g.. respective'ly. and means for controlling the the right, as indicated by the arrow in I"ig.z 18.y v'flow oilfluid between said housings. I This closes the port connections until the ac. l "j 5. A hydraulic ton unit comprising, celerator pedal is raised further to rotate the -in1f o0n1bination.fa-drlve shaft,'a radially slidable valve plug as seen in Fig. 18i to again openther` f vane pump onsaid shaft, a driven-shaft coaxially alined 'with said drive shaft, a radiallyslidable accelerator pedal is raised to its top limit the Yimefmotrjen Siiifi driven Shaft. mutable drive shaft will be locked against rotation be.. housing-defining pump'and motor chambers for cause the sleeves 60 and 6I will be, inneutral setsaidpump and motorrespectively, means ting in which case iiuid cannot be pumped re-l f o'r the delivery of pressure fluid from said pump 40ftosaid'mot017 and-'of exhaust fluid from said motor togi'said pump, andjmeans for varying the pump 'an motor': capacities simultaneously and in oppositef'senses' from onecondition in which the pump has no eccentricity and the motor hasa maximum yecceninicty to another condition inv pump chamber.

I claim as my invention: Y 1. 'A hydraulic transmission comprising', in combination, coaxially'alined driving, transmis` said driving shaft, a rotary motor unit on the adjacent end of said transmission shait, a com mon housing for said units, a pair of eccentric sleeves rotatably mounted within said housing and peripherally dening pump and motor chambers respective1y,'a ported division plate between said units, actuating means vfor 'rotating said A sleeves to" vary the capacities of said units simu l taneou'sly and in opposite senses, and'a control couple drivingly connected between said trans'- lnission and driven shafts, said couple including means connected ,with said. ,actuat ing Jmeansior producing control vmovements responsive jointly to the speed of rotation and the load demand at'l said couple.

2. A torque amplifying transmission comprising, in i combination, eoaxialiy alinea driving,A

transmission and driven shafts; arotary pump on said driving shaft, a rotary motor on the adjacentendof said driven shaft. port means for the passage of pressure :duid froml said pump to said motor, means for varying the. capacities of said pump and said motor simultaneously and in opposite senses, a control couple drivingly connected between said transmission and driven shafts', said couple includingmeans for producing control movement in changes in the'speed yof rotation of said couple and thefload demand on said'ccuple, and means for transmitting said control movement to the 75 accordance with 6. In a hydraulic transmission apparatus, the

combination of a fluid pump adapted for connection to a source of rotary 'powerL a fluid motor coaxially alined with said pump and adapted v to' deliver rotary power to a driven member, said pump and said motor being of the radially slidable vvane type. eccentric sleeves defining theinner peripheralisurfacesiof-the pump and.mo tor chambers, means for rotating said sleeves' to' vary the volumetric delivery and capacity or the .o pump and motor respectively and in oD'pOeite senses, a portedf division-p1ate between said pump and said motor for the passage of pressure fluid from the pump to the motor and for the return passage of exhaust iluid from the' motor to 3 5v the pump, and meansy for rotating saiddivision plate concurrently with the' rotation of saidsleeves to follow the axes of Sylmnvetry between said' pump and said motor.

'7. A torque multiplying hydraulic transmis- 7o sijon comprising, in combination, coaxially alined rotary shafts, a variable ycapacity rotary hy-y draulicunit on thev adjacent end of eacliof saidshafts, a housingdeilning a common enclosing chamber forsaid units. said umts being oil' the radial slidable vane type, the venes oi said units and the load torque of said driven shaft, and means for transmitting said relativerotational movement to said control means. -1 Y t 13. A torque amplifying transmission comprising, in combinationd'riving and transmission shafts, variable capacityv power ytransmitting* means connected between said shafts, a driven in, weighted studs drivinglyconnected between# coaxially alinedwith said transmission shaft; a

flexible control couple [for transmitting power between said transmission shaft and said driven shaft; said couple including a pair of disks rigid with said transmission anddriven shafts respectively and disposed in face-to-face relation, centrifuge means drivingly connectedY between said disks and radially slidable therein to produce relative rotational movement between said disks in accordance-with the speed of rotation and' the load torque of said driven shaft; and means for transmitting such movement to adjust said variable capacity driving connection between said drive and transmission shafts.

' 9. A hydraulic transmission apparatus lcomprising, in combination, hydraulic pump and motor units connected together in a closed hydraulic system, means for driving the pump unit,

a shaft driven by the motor unit, and means for automatically varying the volumetric capacity lof one of said umts, said means including an automatic control couple on said shaft responsive jointly to the speed of rotation and the load torque at said couple to transmit control movement to said one unit.

10. In a hydraulic transmission, the combination of ahydraulic pump and motor connected in a closed hydraulic system, means for varying the respective volumetric delivery and capacity of said pump and motor simultaneouslyand in lopposite senses, and control means for effect-Y shaft, a member rigid 'on said transmission shaft); a member rigid on said driven shaft, said mem y; bers having reversely formed contour slots there,y 'f

said members and radiallyfslidable in said slots; to produce relativeangular rotation between saidJA members, the contour of said slots being such; that in any radial position of said studs the centrifugal force thereon is balanced by the torque momentexerted by the members at that position, and means for transmitting said .angular rotation to vary the capacity of said power transmitting means. 14. A transmission mechanism comprising, in combination, driving and transmission shafts .having a variable capacity driving connection said disks respectively, means responsive to cening such( variation automatically'in response to variations in load demand, said control means being independent of the power input.

tion, a driving member, a driven member, a variable driving connection between said members adjustable to change the power transmission ratio, and control means for` adjusting said connection in accordance with a balance condition between the component of centrifugal ,force .acting on said means determined by the speed of 4rotation of said driven member and the componentof the torque moment acting. on said Ameansdetermined by the load on said driven member. 12. A hydraulic transmission comprising, in combination, a hydraulic pump andmotor connected together in a closed hydraulic system, control means for varying the volumetric Adelivery rate of the pump and the capacity of the motor simultaneously and in opposite senses, a

transmission shaft driven by said motor,'a diskA I 11. A transmission comprising, 1n combinatrifugal force radially slidable in said contour slots to produce relative rotational control movement between said disks, the curveof each slot being generated in accordance with the formula where a isthe angle between the center ofthe disk and a tangent to the curve, Fc 'is the centrifugal force exerted by said means,'and F is the torque moment 'at the point of tangency.

15. In combination with a transmission having a pair of shafts with a variable capacity driving connection therebetween, a flexible con- Y trol couple adapted to transmit power from the driven end of said transmission to a driven member, said couple including a driving member and adriven member disposed in face-to-face relation, contour slots reversely formedinsaid members, means responsive to centrifugal force drivingly connected between said members and radially slidable in said slots to produce relative angular rotational movementbetween said members, the curve of said slots being generated in accordance with the formula,

tation of said members and a. tangent to the l curve, Fc isi-the centrifugal force of said means at the point of tangency and F is the torque moment at said point, and means for transmitting said relative rotational movement to vary the capacity of said driving connection.

16. A transmissionmechanism comprising, in combination, coaxially alined driving, .transmission and driven shafts, a pair of hydraulic rotor units' on the adiacent ends of said vdriving and transmission shafts, a common .housing `for said umts, a pair of eccentric sleeves peripherally deining hydraulic chambe s for said units respec` -tively and 4rotatalzolein s d housing to vary the capacities of said units, rteans connecting said tuatinggmeansg means being. rotatable-with' said-mechanism when assas'ss units in 'ciones hydraulic system,- scid nonsing bcing rotatable with said units when tlie driving .ratio between the driving and transmission 'shafts is one-to-one, a control coupling drivingly connected between said transmission land saidA driven 'shaftspermitting relative angular rotation therebetween .responsive to speed and load changes,

units on the adjacent ends of 4said driving and transmission shafts, a common housing for. said umts, means movable in said housing to vary combination. driving ons driven shorts, driving means connected between said shafts and' ad- ;lustable'to vary the transmission ratio therein-.

- tween,v control means responsive jointly to the speed and load ofthe driven shaft for varying said ratio, and manually supervised means for controlling said ratio independently of 'said control means when the loadtorque on said driven shaftis reversed) 22. A transmission mechanism comprising, in

combination, coaxially alined driving, transmis" sion and driven shaits, a variable capacity drivthe capacities of said units,- means-connectin'g said units in closed hydraulic system, said housing being rotatable with said umts when the driving ratio between-the'driving and transmission shafts is one-to-one, `a control coupling drivingly connected between said transmission and said i driven shafts permitting relative angular yrotation therebetweenresponsive to speed and load. changes, and mechanism for transmitting such rotational control movement to said movable means uniformly ing or stationary.

ing connection between said driving and transmission shafts, a control coupling drivingly connected between said transmission and .driven shafts for producing control movementfresponsive to theflcad-on said driven shaft, means vfor transmitting such movement to vary -thexcapacity of said connection, and manually supervised control means for varying said capacity independently of said control couple.

23.A n mechanismcomprising, in combination, driving and driven members, a var..

iable transmission fmechanism connected between saidmembers, control means for automatically varying the transmission ratio in inwhether said housing .is rotatllil. A transmission mechanism comprising, in

combination, vc'a'xially alinea` driving, transmission and driven shafts, a variable capacity driv-G ing connection betWeerrsaid ydriving and said transmission shafts; including normally s tationary actuating meansrotatable withsaid driving Y verse ratio to 'the load torque on'said` driven member when the driven member is rotating in one direction, and manually supervised means for varying the transmission ratio independently of. said control means when saiddriven member isrotating in the opposite direction.

comprising, in,combination, an internal combustion engine, a change-speed transmission drivinglvv connected between said engine and a dedrivingly connected between f viceito be driven, means for varying the driving and driven shafts permitting relative angular rotational movement therebetween responsive to 'speed and `load changes, and mechanism Yffor transmitting 'such 'movement to said-actuating means unvaryingly irrespectiveof its rotationj.

of said transmission vbetween neutral and' 4(*engiri'e-means .responsive to initial accelerator l19. `A transmission mechanism comprising, in

combination, i driving and transmission shafts having a variable capacity -driivng mechanism' connectedtherebetween, normally stationary -acvaryingsuch capacity, said the ratio therebetweenfjs 0ne-tocne,"a flexible y control coi i p1c onssidusnsrnission shaft adapted 'i for .connection withr a' drivenme'm'ben said couple permittingrelative fangularrotational movement between said transmission-shaft and the" driven member responsive to speed"and load changes,` and mechanismfor transmitting such angular rotational" movement, to said actuating means i whether -itis rotating orgsta'tionary.'

f 20. A transmission-'mechanism comprising. in combination coaxiallyalined driving,- transmis- 4sion and driven shafts, a pair of rotary hydraulic units on the' .adjacent 'ends or said-gdriving and .capacities of said umts to change the torquespeedratio between said'driving and transmis-' 'rotation therebetween responsive. tospeed and load changes, and mechanismfor transmitting such rotational control movement to said means irrespective of the rotation of said housing.

. d comprising, in

' depression for drivingly engaging said transmission,- and means forautomatically effecting the .variations in the driving ratio after engagement, r[said last named means being responsive jointly gto-the torque demand and the speed oi' rotation or soie driven device.

' transmission shafts connected together in closed hydraulic system, means f or varyingthe relativev 25. Mechanism of the fcharacter described-V -comprising, in combination, an internal combustion engine, .a change-speed transmission drivingly connected between said engine and a device to be driven, said transmissionl beingA variable n neutral and a onein minute increments bet t oone1driving ratio, caid ransmission being 0D- rev'ersal of load torqueian accelerator -for said engine, said accelerator an initial range f of" depression prior to co rol of said engine,

responsive to depressi n of said accelerator through said initial range for engaging said transmission, means lfor controlling the driving ratio of saidtransmission automatically after engagement, and means for controlling the degree of braking exerted .by said transmission on said driven-device in accordance with the position of said accelerator in said initialrange.

l 26. Mechanism of the character described Vins ratio between said comprising, in combination, a "driving member,

a driven member, a variable speed transmission between said driving and driven members, an

24. Mechanismof the character described ajo'ne-to-'one ratio, an accelerator'pedal for said aerativeas a vbrake on'said driven device upon' accelerator 'pedal for.` said driving member, means` responsive to initial movement ofsaid accelerator pedal for engaging said on, and

means responsive to movements of. said accelerator pedal withinits range of initial movement for controlling the degree of braking exerted by `said transmission on said driven member upon reversal ofA load.

27. Mechanism of the character described comprising, in combination, a driver, a driven element, a variable speed transmission connected between said driver and driven element, said transmission being variable in minute increments upon reversalv of load torque forexerting a variable braking effect upon said driven element, a lever for controlling the speed of rotation of said driver, said lever having a range of initial movement prior to control of said driver, and means responsive to movements, of said lever Within said initial range for controlling the degreeof braking eiect exerted by said transmis` sion on said driven element.

28. Mechanism of the lcharacter described comprising, in combination, an internal combustion engine, a variable speed transmission drivingly connected between said engine and a device to be driven, means responsive to the load and speed of said driven device for controlling the transmission ratio, and manually supervised control means for adjusting said transmission tov variably brake said driven device upon reversal of load torque.4

29. Mechanism of the character described in' cluding, in combination, a variable capacity brake-mechanism, a control lever for said brake mechanismshiftable' incrementally to control the braking effect of said mechanism, a pressure liuid operated actuator for said lever, valve means for controlling the flow of pressure uid to said actuator, manually operable means for said valve means shiftable to cause fluid tov flow to said actuator, and means in said valve responsive to movement of said actuator for stopping the flow of iluid from said valve to said actuator until said manual means is again shifted, whereby toeiect limit control of said actuator responsive to limit movements of said manual means.

assenze 32. Mechanism of the character described comprising, in combination, coaxially alined driving and driven shafts, a variable capacity rotary hydraulic unit on the adjacent end of each of said shafts, a housing defining a common hydraulic chamber for said units, means for controlling the distribution of fluid between said units, means supporting said housing for 'rotation by the fluid pressure of said units, means for selectively controlling the rotation of said housing, means including a control lever shiftable selectively in one direction or the other for eifecting forward or reverse rotation of said driven shaft, a pressure operated actuator for said control lever, a selector for holding said lever centered in neutral position, said selector being shiftable selectively to permit movement of said lever in one direction or the other, and manually operated means for controlling said selector and the means for controlling the rotation of said housing conjointly.v

v33. Mechanismiof the character described comprising, in combination, driving means, a variable speed transmission drivingly connected between said means and a device to be driven, a control lever shiftable in one direction to engage said transmission for forward speed operation and shiftable in the opposite direction for reverse, a pressure operated actuator for said control lever, a manually operated selector for holding said lever in central neutral position, said selector being selectively shiftable to permit said lever to move in one direction or the other, and a valve mechanism for said actuator manually controlle conjolntly with said selector. Y

, reversal to permit free wheeling of said device.

celerator for said engine connected to control said valve means upon initial depression prior to engine control to cause uid to ow to said actuator, and means in said valve responsive to movement of said actuator for stopping the flow of fluid from ,said vvalve'to said actuator until said accelerator is further depressed,'whereby to e`ffect limit :control of said actuator responsive to,

- limit movements ofsaid manual means.

, comprising, in comb motor units connected gether in closed hydrau- 35. A mechanism'of the character described comprising, in combination, a driving means, a variable capacity hydraulic pump. driven by said means, a vane type hydraulic motor having a rotatable housing dening the pump chamber and connected to receive pressure fluid from said pump, a device driven by said motor, means for controlling the volumetric -displacement of said pump between zero and maximum', said last named means automatically seekingl zero displacement control positionv upon reversal of the load torque, and means for locking said housing against rotation and rleasable to permit rotation of said housing upon auch reversal of load torque,

whereby topermit freie wheeling` said device.

36. A mechanism o the character described rij/tion, hydraulic pump and lic system,=A means fo driving said pump unit, a device driven by said motor unit, and means .for automatically controllingl one of said units be- A tween zero and maximum volumetric displacement.. said last named means automatically seek- I0A ing a zero displacement'control position upon reversal of load torque.

FREDERICK O. JOHNISON. 

